Touch sensor and display device

ABSTRACT

A display device includes: a base substrate; a light emitting element located on the base substrate; a thin-film encapsulation layer located on the light emitting element; touch electrodes located on the thin-film encapsulation layer, each of the touch electrode including an opening; and a strain gauge including: resistance lines located in the openings, respectively, the resistance lines located in the same layer as the touch electrodes and having variable resistance values changed in response to a touch input; a first connection line connecting two resistance lines neighboring each other along a first direction; and a second connection line connecting two resistance lines neighboring each other along a second direction, the second direction intersecting the first direction, wherein the first connection line and the second connection line are located between the thin-film encapsulation layer and the resistance lines.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.16/560,318, filed on Sep. 4, 2019, and claims priority from and thebenefit of Korean Patent Application No. 10-2018-0122358, filed on Oct.15, 2018, each of which is hereby incorporated by reference for allpurposes as if fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate generally to a touchsensor and a display device.

Discussion of the Background

Electronic devices that provide images to a user, such as a smartphone,a tablet PC, a digital camera, a notebook computer, a navigation system,and a smart television, include a display device for displaying images.The display device includes a display panel that generates and displaysan image and various input devices.

Recently, a touch sensor that recognizes a touch input has been widelyapplied to display devices mainly in smartphones and tablet PCs. Due tothe convenience of a touch method, the touch sensor is replacing anexisting physical input device such as a keypad.

Regarding the touch sensor that detects a touch position, research hasbeen recently made to apply a pressure sensor for detecting theintensity of pressure to a display device and utilize the pressuresensor in place of existing physical buttons.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

Devices constructed according to exemplary implementations of theinvention provide a touch sensor capable of sensing pressure.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

According to one or more embodiments of the invention, a touch sensorincludes a base layer; first touch electrode members, each of the firsttouch electrode members including: first touch electrodes arranged onthe base layer along a first direction and electrically connected toeach other along the first direction; and first openings, each of thefirst touch electrodes including one of the first openings; second touchelectrode members, each of the second touch electrode members including:second touch electrodes arranged on the base layer along a seconddirection and electrically connected to each other along the seconddirection, the second direction intersecting the first direction; and astrain gauge including rows of resistance lines arranged along thesecond direction, each of the rows of resistance lines including:resistance lines arranged in the first direction and electricallyconnected to each other along the first direction, wherein each of thefirst touch electrode members are arranged and spaced apart from eachother along the second direction, wherein the resistance lines arelocated in the first openings, respectively, and wherein two neighboringrows of resistance lines are electrically connected to each other.

Each of the rows of resistance lines may include: the resistance linesall connected to each other in series.

A resistance line located at a distal end of a first row of resistancelines and a resistance line located at a distal end of a second row ofresistance lines adjacent to the first row of resistance lines along thesecond direction may be electrically connected to each other.

The resistance line located at the distal end of the first row ofresistance lines and the resistance line located at the distal end ofthe second row of resistance lines may be disposed in the same electrodecolumn.

The first touch electrodes, the second touch electrodes and theresistance lines may be all located in a first layer and made of thesame material.

The first touch electrode member may further include: a first connectionportion connecting two of first touch electrodes neighboring each otheralong the first direction, wherein the second touch electrode member mayfurther include: a second connection portion connecting two of secondtouch electrodes neighboring each other along the second direction, thesecond connection portion being insulated from the first connectionportion, wherein the strain gauge may further include: a firstconnection line connecting two neighboring resistance lines in the samerow of resistance lines; and a second connection line connecting twoneighboring resistance lines located at respective distal ends ofdifferent rows of resistance lines neighboring each other along thesecond direction, wherein one of the first connection portion and thesecond connection portion is located in a second layer different fromthe first layer, wherein the other one of the first connection portionand the second connection portion is located in the first layer, andwherein the first connection line and the second connection line arelocated in the second layer.

The touch sensor may further include: an insulating layer located on thebase layer, wherein the first connection line and the second connectionline may be located on the base layer, wherein the insulating layer islocated on the first connection line, wherein the first touchelectrodes, the second touch electrodes and the resistance lines may belocated on the insulating layer, and wherein the insulating layer may belocated between the resistance lines and the first connection line.

The touch sensor may further include: a plurality of branches located ineach of the first openings and connected to each of the resistancelines, spaced apart from each other, wherein the branches may be made ofthe same material as the resistance lines.

The touch sensor may further include: a controller connected to thefirst touch electrode member, the second touch electrode member and thestrain gauge, wherein the controller may be configured to: detect aposition of a touch input based on a change in capacitance between afirst touch electrode and a second touch electrode caused by the touchinput; and detect the pressure of the touch input based on a change in aresistance value of the strain gauge caused by the touch input.

The controller may include: a Wheatstone bridge circuit which iselectrically connected to the strain gauge.

The touch sensor may further include: a first signal line electricallyconnecting a first end of the strain gauge and the Wheatstone bridgecircuit; and a second signal line electrically connecting a second endof the strain gauge and the Wheatstone bridge circuit, wherein a sensingarea in which the first touch electrodes, the second touch electrodesand the resistance lines may be located and a peripheral area which islocated around the sensing area are defined in the base layer, andwherein the first signal line and the second signal line may be locatedin the peripheral area and are all located on a side of the sensingarea.

The Wheatstone bridge circuit may include: a first node configured toreceive a driving voltage and electrically connected to a first end ofthe strain gauge; a second node configured to receive a referencevoltage; a first output node which is electrically connected to a secondend of the strain gauge; a second output node; a first resistorconnected between the second node and the second output node; a secondresistor connected between the first node and the second output node;and a third resistor connected between the second node and the firstoutput node.

The resistance value of the strain gauge, a resistance value of thefirst resistor, a resistance value of the second resistor, and aresistance value of the third resistor may be substantially equal when atouch input is not applied.

The touch sensor may further include: a plurality of dummy electrodeslocated on the base layer, wherein each of the second touch electrodesmay include a second opening, wherein the first touch electrodes, thesecond touch electrodes, and the resistance lines may be all located ina first layer, wherein the dummy electrodes may be located in the secondopenings, spaced apart from the second touch electrodes and are locatedin the first layer, and wherein the first touch electrodes, the secondtouch electrodes, the resistance lines, and the dummy electrodes may bemade of the same material.

An area of each of the second openings may be larger than that of eachof the first openings.

The second touch electrodes may be driving electrodes, and the firsttouch electrodes are sensing electrodes.

According to one or more embodiments of the invention, a touch sensorincludes a base layer; first touch electrode members, each of the firsttouch electrode members including: first touch electrodes arranged onthe base layer along a first direction and electrically connected toeach other along the first direction; second touch electrode members,each of the second touch electrode members including: second touchelectrodes arranged on the base layer along a second directionintersecting the first direction and electrically connected to eachother along the second direction; and first openings, each of the secondtouch electrodes including one of the first openings; and a strain gaugeincluding rows of resistance lines arranged along the second direction,each of the rows of resistance lines including: resistance linesarranged in the first direction and electrically connected to each otheralong the first direction, wherein each of the second touch electrodemembers are arranged and spaced apart from each other along the firstdirection, wherein the resistance lines are located in the firstopenings, respectively, and wherein two neighboring rows of resistancelines are electrically connected to each other.

Each of the rows of resistance lines may include: the resistance linesall connected to each other in series.

A resistance line located at a distal end of a first row of resistancelines and a resistance line located at a distal end of a second row ofresistance lines adjacent to the first row of resistance lines along thesecond direction are electrically connected to each other.

The first touch electrode member further includes: a first connectionportion connecting two of first touch electrodes neighboring each otheralong the first direction, wherein the second touch electrode memberfurther includes: a second connection portion connecting two of secondtouch electrodes neighboring each other along the second direction, thesecond connecting portion being insulated from the first connectionportion, wherein the first touch electrodes and the second touchelectrodes are all located in a first layer, wherein one of the firstconnection portion and the second connection portion is located in asecond layer different from the first layer, wherein the other one ofthe first connection portion and the second connection portion islocated in the first layer, and wherein the resistance lines are locatedin the first layer or the second layer.

The resistance lines may be located in the first layer, and the firsttouch electrodes, and wherein the second touch electrodes and theresistance lines may be made of the same material.

The strain gauge may further include: a first connection line connectingresistance lines located in the same row of resistance lines; and asecond connection line connecting two neighboring resistance lineslocated in different rows of resistance lines neighboring each otheralong the second direction, and the first connection line and the secondconnection line may be located in a different layer from the resistancelines.

The touch sensor may further include a plurality of dummy electrodeslocated on the base layer, wherein each of the first touch electrodesmay include a second opening, wherein the first touch electrodes, thesecond touch electrodes, and the resistance lines may be all located ina first layer, wherein the dummy electrodes may be located in the secondopenings, spaced apart from the first touch electrodes and are locatedin the first layer, and wherein the first touch electrodes, the secondtouch electrodes, the resistance lines, and the dummy electrodes may bemade of the same material.

According to one or more embodiments of the invention, a touch sensorincludes a base layer; first touch electrode members, each of the firsttouch electrode members including: first touch electrodes arranged onthe base layer along a first direction and electrically connected toeach other along the first direction; first openings, each of the firsttouch electrodes including one of the first openings; second touchelectrode members, each of the second touch electrode members including:second touch electrodes arranged on the base layer along a seconddirection intersecting the first direction and electrically connected toeach other along the second direction; second openings, each of thesecond touch electrodes including one of the second openings; and astrain gauge including: rows of first resistance lines arranged alongthe second direction, each of the rows of resistance lines including:resistance lines arranged in the first direction and electricallyconnected to each other along the first direction; and rows of secondresistance lines arranged along the second direction, each of the rowsof resistance lines including: resistance lines arranged in the firstdirection and electrically connected to each other along the firstdirection, wherein each of the first touch electrode members arrangedand are spaced apart from each other along the second direction, whereineach of the second touch electrode members arranged and are spaced apartfrom each other along the first direction, wherein the first resistancelines are located in the first openings and spaced apart from the firsttouch electrodes, respectively, and the second resistance lines arelocated in the second openings and spaced apart from the second touchelectrodes, respectively, and wherein one of the first resistance linesand one of the second resistance lines neighbor each other along thesecond direction are electrically connected to each other.

The first touch electrodes, the second touch electrodes, the firstresistance lines, and the second resistance lines may be located in thesame layer and made of the same material.

A length of each of the second resistance lines may be different fromthat of each of the first resistance lines.

An area of each of the second openings may be larger than that of eachof the first openings, and the length of each of the second resistancelines may be greater than that of each of the first resistance lines.

The strain gauge may further include: a connection line connecting afirst resistance line located at a distal end of a row of firstresistance line and a second resistance line located at a distal end ofa row of second resistance line adjacent to the row of first resistanceline along the second direction, wherein the connection line may belocated in a different layer from the first touch electrodes and thesecond touch electrodes.

According to one or more embodiments of the invention, a display deviceincludes: a base substrate; a light emitting element located on the basesubstrate; a thin-film encapsulation layer located on the light emittingelement; touch electrodes located on the thin-film encapsulation layer,each of the touch electrode including an opening; and a strain gaugeincluding: resistance lines located in the openings, respectively, theresistance lines located in the same layer as the touch electrodes andhaving variable resistance values changed in response to a touch input;a first connection line connecting two resistance lines neighboring eachother along a first direction; and a second connection line connectingtwo resistance lines neighboring each other along a second direction,the second direction intersecting the first direction, wherein the firstconnection line and the second connection line are located between thethin-film encapsulation layer and the resistance lines.

The thin-film encapsulation layer may include: a first encapsulatinginorganic layer located on the light emitting element; an encapsulatingorganic layer located on the first encapsulating inorganic layer; and asecond encapsulating inorganic layer located on the encapsulatingorganic layer, wherein the touch electrodes and the strain gauge may belocated on the second encapsulating inorganic layer.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 is a schematic diagram of a display device according to anexemplary embodiment.

FIG. 2 is a block diagram of a touch sensor illustrated in FIG. 1.

FIG. 3 illustrates the touch sensor of FIG. 1, a plan view of a sensorunit of the touch sensor, and the connection relationship between thesensor unit and a controller.

FIG. 4 is an enlarged plan view of a portion Q1 of FIG. 3.

FIG. 5 illustrates the structure of a first layer of the sensor unit ofFIG. 4.

FIG. 6 is an enlarged plan view of a portion Q2 of FIG. 5 including aresistance line.

FIGS. 7 and 8 illustrate modified examples of the resistance line ofFIG. 6.

FIG. 9 illustrates a modified example of the structure of the resistanceline of FIG. 6.

FIG. 10 is an enlarged plan view of a portion Q3 of FIG. 5.

FIG. 11 illustrates the structure of a second layer of the sensor unitof FIG. 4.

FIG. 12 is a cross-sectional view taken along a sectional line X1-X1′ ofFIG. 4.

FIG. 13 is a cross-sectional view taken along a sectional line X2-X2′ ofFIG. 4.

FIG. 14 is a cross-sectional view taken along a sectional line X3-X3′ ofFIG. 4.

FIG. 15 is a cross-sectional view illustrating a modified structure ofFIG. 12.

FIG. 16 is a cross-sectional view illustrating a modified structure ofFIG. 13.

FIG. 17 is a cross-sectional view illustrating a modified structure ofFIG. 14.

FIG. 18 is an enlarged plan view of a portion Q4 of FIG. 5.

FIG. 19 is a cross-sectional view of the sensor unit and a display paneltaken along a sectional line X4-X4′ of FIG. 18.

FIG. 20 is a diagram for explaining a touch position detection operationof the touch sensor according to an exemplary embodiment.

FIG. 21 is a plan view schematically illustrating the arrangement of astrain gauge, a first signal line and a second signal line illustratedin FIG. 3 and the connection relationship of the strain gauge, the firstsignal line and the second signal line with a Wheatstone bridge circuit.

FIG. 22 is a circuit diagram of the Wheatstone bridge circuitelectrically connected to the strain gauge of FIG. 21 explaining a touchpressure detection operation of the touch sensor according to anexemplary embodiment.

FIG. 23 is a plan view of a sensor unit of a touch sensor according toan exemplary embodiment and illustrates the connection relationshipbetween the sensor unit and a controller.

FIG. 24 is a plan view of a sensor unit of a touch sensor according toan exemplary embodiment and illustrates the connection relationshipbetween the sensor unit and a controller.

FIG. 25 is an enlarged view of a portion Q5 of FIG. 24.

FIG. 26 illustrates the structure of a first layer of the sensor unit ofFIG. 25.

FIG. 27 illustrates the structure of a second layer of the sensor unitof FIG. 25.

FIG. 28 is a cross-sectional view taken along a sectional line X11-X11′of FIG. 25.

FIG. 29 is a cross-sectional view taken along a sectional line X12-X12′of FIG. 25.

FIG. 30 is a cross-sectional view taken along a sectional line X13-X13′of FIG. 25.

FIG. 31 is a cross-sectional view taken along a sectional line X14-X14′of FIG. 25.

FIG. 32 is a cross-sectional view illustrating a modified structure ofFIG. 28.

FIG. 33 is a cross-sectional view illustrating a modified structure ofFIG. 29.

FIG. 34 is a cross-sectional view illustrating a modified structure ofFIG. 30.

FIG. 35 is a cross-sectional view illustrating a modified structure ofFIG. 31.

FIG. 36 is a plan view of a sensor unit of a touch sensor according toan exemplary embodiment and illustrates the connection relationshipbetween the sensor unit and a controller.

FIG. 37 is an enlarged view of a portion Q6 of FIG. 36.

FIG. 38 illustrates the structure of a first layer of the sensor unit ofFIG. 37.

FIG. 39 illustrates the structure of a second layer of the sensor unitof FIG. 37.

FIG. 40 is a cross-sectional view taken along a sectional line X21-X21′of FIG. 37.

FIG. 41 is a cross-sectional view taken along a sectional line X22-X22′of FIG. 37.

FIG. 42 is a cross-sectional view illustrating a modified structure ofFIG. 40

FIG. 43 is a cross-sectional view illustrating a modified structure ofFIG. 41.

FIG. 44 is a plan view of a sensor unit of a touch sensor according toan exemplary embodiment and illustrates the connection relationshipbetween the sensor unit and a controller.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various exemplary embodiments maybe practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid unnecessarilyobscuring various exemplary embodiments. Further, various exemplaryembodiments may be different, but do not have to be exclusive. Forexample, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

Further, in the accompanying drawings, the size and relative sizes ofelements may be exaggerated for clarity and/or descriptive purposes.When an exemplary embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the X-axis, the Y-axis,and the Z-axis are not limited to three axes of a rectangular coordinatesystem, such as the x, y, and z-axes, and may be interpreted in abroader sense. For example, the X-axis, the Y-axis, and the Z-axis maybe perpendicular to one another, or may represent different directionsthat are not perpendicular to one another. For the purposes of thisdisclosure, “at least one of X, Y, and Z” and “at least one selectedfrom the group consisting of X, Y, and Z” may be construed as X only, Yonly, Z only, or any combination of two or more of X, Y, and Z, such as,for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions, but are to include deviations in shapes that result from,for instance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

As customary in the field, some exemplary embodiments are described andillustrated in the accompanying drawings in terms of functional blocks,units, and/or modules. Those skilled in the art will appreciate thatthese blocks, units, and/or modules are physically implemented byelectronic (or optical) circuits, such as logic circuits, discretecomponents, microprocessors, hard-wired circuits, memory elements,wiring connections, and the like, which may be formed usingsemiconductor-based fabrication techniques or other manufacturingtechnologies. In the case of the blocks, units, and/or modules beingimplemented by microprocessors or other similar hardware, they may beprogrammed and controlled using software (e.g., microcode) to performvarious functions discussed herein and may optionally be driven byfirmware and/or software. It is also contemplated that each block, unit,and/or module may be implemented by dedicated hardware, or as acombination of dedicated hardware to perform some functions and aprocessor (e.g., one or more programmed microprocessors and associatedcircuitry) to perform other functions. Also, each block, unit, and/ormodule of some exemplary embodiments may be physically separated intotwo or more interacting and discrete blocks, units, and/or moduleswithout departing from the scope of the inventive concepts. Further, theblocks, units, and/or modules of some exemplary embodiments may bephysically combined into more complex blocks, units, and/or moduleswithout departing from the scope of the inventive concepts.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Hereinafter, embodiments will be described with reference to theaccompanying drawings.

FIG. 1 is a schematic diagram of a display device 1 according to anexemplary embodiment, and FIG. 2 is a block diagram of a touch sensorTSM illustrated in FIG. 1.

Referring to FIGS. 1 and 2, the display device 1 according to theexemplary embodiment includes the touch sensor TSM and a display panel300 and may further include a display panel driver 400. The touch sensorTSM includes a sensor unit 100 and a controller 200.

In the exemplary embodiment of FIG. 1, the sensor unit 100 and thedisplay panel 300 are separated from each other. However, this is justfor ease of description, and the sensor unit 100 and the display panel300 may also be formed integrally with each other.

The display panel 300 includes a display area DA and a non-display areaNDA surrounding at least one side of the display area DA. The displayarea DA includes a plurality of scan lines 310 and a plurality of datalines 320, and a plurality of pixels P connected to the scan lines 310and the data lines 320. The non-display area NDA may include variousdriving signals for driving the pixels P and/or wirings for supplyingdriving power.

In the present disclosure, the type of the display panel 300 is notparticularly limited. For example, the display panel 300 may be aself-luminous display panel such as an organic light emitting displaypanel, a quantum dot light emitting display (QLED) panel, a micro-lightemitting diode (LED) display panel, a nano-LED display panel.Alternatively, the display panel 300 may be a non-luminous display panelsuch as a liquid crystal display (LCD) panel, an electrophoretic display(EPD) panel, or an electrowetting display (EWD) panel. If the displaypanel 300 is a non-luminous display panel, the display device 1 mayfurther include a backlight unit for supplying light to the displaypanel 300. For ease of description, a case where the display panel 300is an organic light emitting display panel will be described below as anexample.

The display panel driver 400 is electrically connected to the displaypanel 300 to supply signals necessary for driving the display panel 300.For example, the display panel driver 400 may include at least one of ascan driver for supplying scan signals to the scan lines 310, a datadriver for supplying data signals to the data lines 320, and a timingcontroller for driving the scan driver and the data driver. According toan exemplary embodiment, the scan driver, the data driver, and/or thetiming controller may be integrated into one display integrated circuit(D-IC). Alternatively, in an exemplary embodiment, at least one of thescan driver, the data driver, and the timing controller may beintegrated or mounted on the display panel 300.

The sensor unit 100 may be provided on at least one area of the displaypanel 300. For example, the sensor unit 100 may be provided on at leastone surface of the display panel 300 to overlap the display panel 300.For example, the sensor unit 100 may be disposed on a surface (e.g., anupper surface) of the display panel 300 in a direction in which an imageis emitted, among both surfaces of the display panel 300. Alternatively,the sensor unit 100 may be formed directly on at least one of bothsurfaces of the display panel 300 or may be formed inside the displaypanel 300. For example, the sensor unit 100 may be formed directly on anouter surface of an upper substrate (or a thin-film encapsulation layer)or a lower substrate (e.g., an upper surface of the upper substrate or alower surface of the lower substrate) of the display panel 300 or may beformed directly on an inner surface of the upper substrate or the lowersubstrate (e.g., a lower surface of the upper substrate or an uppersurface of the lower substrate).

The sensor unit 100 includes a sensing area SA and a peripheral area NSAsurrounding at least a part of the sensing area SA. In some exemplaryembodiments, the sensing area SA may be an area of the sensor unit 100which senses a touch input, and the peripheral area NSA may be an areaof the sensor unit 100 which cannot sense a touch input. According to anexemplary embodiment, the sensing area SA may be disposed to correspondto the display area DA of the display panel 300, and the peripheral areaNSA may be disposed to correspond to the non-display area NDA of thedisplay panel 300. For example, the sensing area SA of the sensor unit100 may overlap the display area DA of the display panel 300, and theperipheral area NSA of the sensor unit 100 may overlap the non-displayarea NDA of the display panel 300.

A plurality of first touch electrode members 120 for detecting a touchinput and a plurality of second touch electrode members 130 fordetecting a touch input may be provided in the sensing area SA of thesensor unit 100.

The first touch electrode members 120 may extend along a first directionX and may be spaced apart from each other along a second direction Yintersecting the first direction X. That is, the first touch electrodemembers 120 extending in the first direction X may be spaced apart fromeach other along the second direction Y to form electrode rows.

The second touch electrode members 130 may extend along the seconddirection Y and may be spaced apart from each other along the firstdirection X. The second touch electrode members 130 may be spaced apartfrom the first touch electrode members 120 and may be insulated from thefirst touch electrode members 120. That is, the second touch electrodemembers 130 extending in the second direction Y may be separated fromeach other along the first direction X to form columns.

The shapes, sizes, and/or arrangement directions of the first touchelectrode members 120 and the second touch electrode members 130 are notparticularly limited. As a non-limiting embodiment, the first touchelectrode members 120 and the second touch electrode members 130 may beconfigured as illustrated in FIG. 3, which will be described later.

The first touch electrode members 120 and the second touch electrodemembers 130 may be electrically connected to the controller 200. In someexemplary embodiments, each of the second touch electrode members 130may be a driving electrode member that receives a driving signal Ts fortouch detection from the controller 200, and each of the first touchelectrode members 120 may be a sensing electrode member that outputs asensing signal Rs for touch detection to the controller 200.

The first touch electrode members 120 and the second touch electrodemembers 130 may overlap at least one electrode of the display panel 300.For example, when the display panel 300 is an organic light emittingdisplay panel, the first touch electrode members 120 and the secondtouch electrode members 130 may overlap a cathode of the display panel300.

A strain gauge 150 may be provided in the sensing area SA of the sensorunit 100 to detect touch pressure. When an external force is applied,the length or cross-sectional area of the strain gauge 150 may bechanged, causing a change in resistance value. The strain gauge 150 maybe spaced apart from the first touch electrode members 120 and thesecond touch electrode members 130 and may be insulated from the firsttouch electrode members 120 and the second touch electrode members 130.

In some exemplary embodiments, at least a portion of the strain gauge150 may extend along the first direction X, like the first touchelectrode members 120.

The controller 200 may be electrically connected to the sensor unit 100to supply the driving signal Ts to the sensor unit 100 and may detect atouch position by receiving the sensing signal Rs corresponding to thedriving signal Ts from the sensor unit 100. In addition, the controller200 may be electrically connected to the strain gauge 150 to detecttouch pressure.

In some exemplary embodiments, the controller 200 may include a touchdriver 210, a touch detector 230, and a pressure detector 250.

The touch driver 210 may provide the driving signal Ts for detecting atouch input to each of the second touch electrode members 130.

The touch detector 230 may detect the presence or absence of a touchinput and/or the position of the touch input by receiving the sensingsignal Rs corresponding to the driving signal Ts from each of the firsttouch electrode members 120. In some exemplary embodiments, the sensingsignal Rs may be a change in mutual capacitance between a first touchelectrode member 120 and a second touch electrode member 130. Morespecifically, when a touch input occurs, the mutual capacitance ischanged at the position of the touch input or around the position of thetouch input. The touch detector 230 may receive a change in mutualcapacitance between each first touch electrode member 120 and eachsecond touch electrode member 130 as the sensing signal Rs and detectthe presence or absence and/or position of a touch input by using thesensing signal Rs.

In some exemplary embodiments, the touch detector 230 may include atleast one amplifier 231 for amplifying a received sensing signal Rs, ananalog-digital converter (ADC) 233 connected to an output terminal 231 cof the amplifier 231, and a processor 235. This will be described inmore detail later with reference to FIG. 20.

The pressure detector 250 may be electrically connected to the straingauge 150 and may detect touch pressure based on a change in theresistance value of the strain gauge 150. In some exemplary embodiments,the pressure detector 250 may include a Wheatstone bridge circuit thatis electrically connected to the strain gauge 150.

In some exemplary embodiments, the touch driver 210, the touch detector230, and the pressure detector 250 may be integrated into one touch IC.

In some exemplary embodiments, the touch driver 210 and the touchdetector 230 may be integrated into one touch IC, and the pressuredetector 250 may be located in a portion other than the inside of thetouch IC. For example, the pressure detector 250 may be disposed on thedisplay panel 300 or on a separate flexible circuit board.

The touch sensor TSM will now be described in more detail byadditionally referring to FIGS. 3 through 14.

FIG. 3 illustrates the touch sensor TSM of FIG. 1, a plan view of thesensor unit 100 of the touch sensor TSM, and the connection relationshipbetween the sensor unit 100 and the controller 200. FIG. 4 is anenlarged plan view of a portion Q1 of FIG. 3. FIG. 5 illustrates thestructure of a first layer L1 of the sensor unit 100 of FIG. 4. FIG. 6is an enlarged plan view of a portion Q2 of FIG. 5 including aresistance line. FIGS. 7 and 8 illustrate modified examples of theresistance line 151 of FIG. 6. FIG. 9 illustrates a modified example ofthe structure of the resistance line FIG. 6. FIG. 10 is an enlarged planview of a portion Q3 of FIG. 5. FIG. 11 illustrates the structure of asecond layer L2 of the sensor unit 100 of FIG. 4. FIG. 12 is across-sectional view taken along a sectional line X1-X1′ of FIG. 4. FIG.13 is a cross-sectional view taken along a sectional line X2-X2′ of FIG.4. FIG. 14 is a cross-sectional view taken along a sectional line X3-X3′of FIG. 4.

Referring to FIGS. 3 through 14, the sensor unit 100 includes a baselayer 110, the first touch electrode members 120, the second touchelectrode members 130 and the strain gauge 150 and may further includedummy electrodes 190.

The base layer 110 may include the sensing area SA and the peripheralarea NSA. The base layer 110 may be a layer serving as a base of thesensor unit 100. In some exemplary embodiments, the base layer 110 maybe one of the layers constituting the display panel 300. In an exemplaryembodiment in which the sensor unit 100 and the display panel 300 areformed integrally with each other, the base layer 110 may be at leastone of the layers constituting the display panel 300. For example, thebase layer 110 may include a thin-film encapsulation layer of thedisplay panel 300. Alternatively, according to an exemplary embodiment,the base layer 110 may be a rigid substrate or a flexible substrate. Forexample, the base layer 110 may be a rigid substrate made of glass ortempered glass or a flexible substrate made of a thin film of a flexibleplastic material. A case where the base layer 110 is a layer includingat least one (e.g., the thin-film encapsulation layer) of the layersconstituting the display panel 300 will be described below as anexample.

The first touch electrode members 120, the second touch electrodemembers 130 insulated from the first touch electrode member 120, and thestrain gauge 150 insulated from the first touch electrode members 120and the second touch electrode members 130 may be located on the sensingarea SA of the base layer 110.

The first touch electrode members 120 may extend along the firstdirection X and may be spaced apart from each other along the seconddirection Y as described above. Each of the first touch electrodemembers 120 spaced apart from each other along the second direction Ymay form an electrode row. In FIG. 3, eight of the first touch electrodemembers 120 are disposed along the second direction Y to respectivelyform a first electrode row RE1, a second electrode row RE2, a thirdelectrode row RE3, a fourth electrode row RE4, a fifth electrode rowRE5, a sixth electrode row RE6, a seventh electrode row RE7, and aneighth electrode row RE8 arranged sequentially along the seconddirection Y. However, the present disclosure is not limited to thiscase, and the number of the first touch electrode members 120 can bevariously changed.

Each of the first touch electrode members 120 may include a plurality offirst touch electrodes 121 arranged along the first direction X and aplurality of first connection portions 123, each connecting the firsttouch electrodes 121 neighboring each other along the first direction X.In the following description of embodiments, the term “connection” mayencompass “connection” in physical and/or electrical aspects.

In some exemplary embodiments, the first touch electrodes 121 may belocated in the first layer L1. The first touch electrodes 121 may have arhombic planar shape. However, the planar shape of the first touchelectrodes 121 is not limited to the rhombic shape and can be changed tovarious shapes such as a triangle, a quadrilateral other than a rhombus,a pentagon, a circle, and a bar.

The first touch electrodes 121 may include a conductive material.Examples of the conductive material may include metals and alloys of themetals. Examples of the metals may include gold (Au), silver (Ag),aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti), nickel(Ni), neodymium (Nd), copper (Cu), and platinum (Pt). The first touchelectrodes 121 may also be made of a transparent conductive material.Examples of the transparent conductive material may include silvernanowire (AgNW), indium tin oxide (ITO), indium zinc oxide (IZO),antimony zinc oxide (AZO), indium tin zinc oxide (ITZO), zinc oxide(ZnO), tin oxide (SnO₂), carbon nanotube, and graphene.

In some exemplary embodiments, the first touch electrodes 121 may have asingle-layer structure or a multilayer structure. When the first touchelectrodes 121 have a multilayer structure, they may include multiplemetal layers. For example, the first touch electrodes 121 may have athree-layer structure of Ti/Al/Ti.

In some exemplary embodiments, the first touch electrodes 121 may have amesh structure so as not to be visible to a user. When the first touchelectrodes 121 have a mesh structure, they may be arranged to notoverlap light emitting areas of the display panel 300. In other words,mesh hole overlapping a light emitting area, may be defined in each ofthe first touch electrodes 121 having the mesh structure.

In some exemplary embodiments, the first touch electrodes 121 spacedapart from each other along the second direction Y may form electrodecolumns. In FIG. 3, eight of the first touch electrodes 121 are disposedin one column, and the first touch electrodes 121 arranged along thesecond direction Y form a first electrode column CE1, a second electrodecolumn CE2, a third electrode column CE3, a fourth electrode column CE4,a fifth electrode column CE5, a sixth electrode column CE6, a seventhelectrode column CE7, and an eighth electrode column CE8. However, thepresent disclosure is not limited to this case, and the number ofelectrode columns formed by the first touch electrodes 121 can bevariously changed.

Each of the first touch electrodes 121 may include a first opening OP1.For example, at least a central portion of each of the first touchelectrodes 121 may be open to expose a layer located under the firsttouch electrode 121. For example, when an insulating layer IL is locatedunder the first touch electrodes 121, a portion of the insulating layerIL may be exposed through each of the first openings OPL.

Each of the first connection portions 123 may electrically connect thefirst touch electrodes 121 neighboring each other along the firstdirection X and may contact the first touch electrodes 121. In someexemplary embodiments, each of the first connection portions 123 may beconfigured as a bridge-shaped connection pattern. In some exemplaryembodiments, the first connection portions 123 may be located in thesecond layer L2 different from the first layer L1 in which the firsttouch electrodes 121 are located.

In some exemplary embodiments, the insulating layer IL may be locatedbetween the first touch electrodes 121 and the first connection portions123. In some exemplary embodiments, the first connection portions 123located in the second layer L2 may be located on the base layer 110, theinsulating layer IL may be located on the first connection portions 123,and the first touch electrodes 121 located in the first layer L1 may belocated on the insulating layer IL. The first connection portions 123and the first touch electrodes 121 may be connected to and directlycontact each other through first contact holes CH1 formed in theinsulating layer IL.

The insulating layer IL may include an insulating material. In someexemplary embodiments, the insulating material may be an inorganicinsulating material or an organic insulating material. The inorganicinsulating material may include at least one of aluminum oxide, titaniumoxide, silicon oxide, silicon oxynitride, zirconium oxide, and hafniumoxide. The organic insulating material may include at least any one ofacrylic resin, methacrylic resin, polyisoprene, vinyl resin, epoxyresin, urethane resin, cellulose resin, siloxane resin, polyimide resin,polyamide resin, and perylene resin.

The first connection portions 123 may include a conductive material. Insome exemplary embodiments, the first connection portions 123 mayinclude the same material as the first touch electrodes 121 or mayinclude one or more materials selected from the materials exemplified asthe constituent material of the first touch electrodes 121. In someexemplary embodiments, the first connection portions 123 may have asingle-layer structure or a multilayer structure. For example, the firstconnection portions 123 may have a three-layer structure of Ti/Al/Ti.Alternatively, the first connection portions 123 may be made of adifferent material from the first touch electrodes 121.

In the drawings, one first connection portion 123 is disposed betweenfirst touch electrodes 121 neighboring each other along the firstdirection X. However, the number of the first connection portions 123can be variously changed. For example, two or more first connectionportions 123 may be disposed between two of first touch electrodes 121neighboring each other along the first direction X.

The second touch electrode members 130 may extend along the seconddirection Y and may be spaced apart from each other along the firstdirection X as described above. Each of the second touch electrodemembers 130 spaced apart from each other along the first direction X mayform a column. In FIG. 3, seven of second touch electrode members 130are disposed along the first direction X to respectively form a firstcolumn CO1, a second column CO2, a third column CO3, a fourth columnCO4, a fifth column CO5, a sixth column CO6, and a seventh column CO7arranged sequentially along a direction opposite to the first directionX. However, the present disclosure is not limited to this case, and thenumber of the second touch electrode members 130 can be variouslychanged.

Each of the second touch electrode members 130 may include a pluralityof second touch electrodes 131 arranged along the second direction Y anda plurality of second connection portions 133, each electricallyconnecting the second touch electrodes 131 neighboring each other alongthe second direction Y.

The second touch electrodes 131 may be electrically connected to eachother along the second direction Y. In addition, the second touchelectrodes 131 may be spaced apart from each other along the firstdirection X.

In some exemplary embodiments, the second touch electrodes 131 spacedapart from each other along the first direction y may form rows. In FIG.3, eight of the second touch electrodes 131 are disposed in one column,and the second touch electrodes 131 arranged along the first direction yform a first row RO1, a second row RO2, a third row RO3, a fourth rowRO4, a fifth row RO5, a sixth row RO6, a seventh row R7, and an eighthrow RO8. However, the present disclosure is not limited to this case,and the number of rows formed by the second touch electrodes 131 can bevariously changed.

In some exemplary embodiments, a row formed by second touch electrodes131 may be located between two electrode rows formed by first touchelectrode members 120. For example, the first row RO1 may be locatedbetween the first electrode row RE1 and the second electrode row RE2,and the second row RO2 may be located between the second electrode rowRE2 and the third electrode row RE3. That is, a row formed by secondtouch electrodes 131 and a row formed by a first touch electrode member120 may be repeatedly arranged along the second direction Y.

Each of the second touch electrodes 131 may include a second openingOP2. For example, at least a central portion of each of the second touchelectrodes 131 may be open to expose a layer located under the secondtouch electrode 131. For example, when the insulating layer IL islocated under the second touch electrodes 131, a portion of theinsulating layer IL may be exposed through each of the second openingsOP2.

In some exemplary embodiments, the area of each of the second openingsOP2 may be different from the area of each of the first openings OP1.For example, the area of each of the second openings OP2 may be largerthan the area of each of the first openings OP1.

In some exemplary embodiments, the second touch electrodes 131 may belocated in the same first layer L1 as the first touch electrodes 121.The second touch electrodes 131 may have a rhombic planar shape.However, the planar shape of the second touch electrodes 131 is notlimited to the rhombic shape and can be changed to various shapes suchas a triangle, a quadrilateral other than a rhombus, a pentagon, acircle, and a bar.

Each of the second connection portions 133 may electrically connect thesecond touch electrodes 131 neighboring each other along the seconddirection Y and may contact the second touch electrodes 131. In someexemplary embodiments, the second connection portions 133 may be locatedin the same first layer L1 as the first touch electrodes 121 and thesecond touch electrodes 131.

The second connection portions 133 may be insulated from the firstconnection portions 123 and may intersect the first connection portions123. In some exemplary embodiments, the insulating layer IL may belocated between the second connection portions 133 and the firstconnection portions 123.

The second touch electrodes 131 and the second connection portions 133may include a conductive material. In some exemplary embodiments, thesecond touch electrodes 131 and the second connection portions 133 maybe made of the same conductive material as the first touch electrodes121.

In some exemplary embodiments, when the first touch electrodes 121 havea mesh structure, the second touch electrodes 131 and the secondconnection portions 133 may also have a mesh structure.

In some exemplary embodiments, each of the second touch electrodes 131may be a driving electrode that receives the driving signal Ts fordetecting a touch position, and each of the first touch electrodes 121may be a sensing electrode that outputs the sensing signal Rs fordetecting a touch position.

The strain gauge 150 may be located in the sensing area SA of the sensorunit 100. The strain gauge 150 may be located in electrode rows formedby the first touch electrode members 120. For example, the strain gauge150 may be located in the first electrode row RE1, the second electroderow RE2, the third electrode row RE3, the fourth electrode row RE4, thefifth electrode row RE5, the sixth electrode row RE6, the seventhelectrode row RE7, and the eighth electrode row RE8.

The strain gauge 150 may include first resistance lines 151, firstconnection lines 153, and second connection lines 155.

The first resistance lines 151 may be located in the first openings OP1formed in the first touch electrodes 121 and may be spaced apart fromthe first touch electrodes 121. In some exemplary embodiments, the firstresistance lines 151 may be located in the first openings OP1,respectively.

Each of the first resistance lines 151 may be bent to have apredetermined pattern. When pressure having certain intensity is appliedto the sensor unit 100 of the touch sensor TSM, the length orcross-sectional area of the first resistance line 151 is changed. Thechange in the length or cross-sectional area of the first resistanceline 151 causes a change in the resistance value of the first resistanceline 151, and the intensity of the touch pressure may be determinedbased on the changed resistance value.

In some exemplary embodiments, as illustrated in FIG. 6, each of thefirst resistance lines 151 may include two or more bent portions and aportion extending in a direction intersecting the first direction X andthe second direction Y in plan view.

The shape of each of the first resistance lines 151 can be variouslychanged. For example, as illustrated in FIG. 7, a first resistance line151-1 may include a plurality of bent portions and a portion extendingparallel to the first direction X in plan view. In another exemplaryembodiment, a first resistance line 151-2 may be formed in an angularspiral shape as illustrated in FIG. 8 or may be formed in a circularspiral shape.

In some exemplary embodiments, the first resistance lines 151 may belocated in the same first layer L1 as the first touch electrodes 121 andthe second touch electrodes 131.

The first resistance lines 151 may include a conductive material. Insome exemplary embodiments, the first resistance lines 151 may be madeof the same material as the first touch electrodes 121 and the secondtouch electrodes 131.

When the first and second touch electrodes 121 and 131 have a meshstructure, each of the first resistance lines 151 may be formed byremoving a portion of a mesh structure. When each of the firstresistance lines 151 is formed by removing a portion of a meshstructure, a plurality of branches BR connected to the first resistanceline 151 and spaced apart from each other may be further located in eachfirst opening OP1 in some exemplary embodiments, as illustrated in FIG.9.

The branches BR may be portions remaining after the removal of a portionof the mesh structure. The branches BR may be spaced apart from thefirst touch electrodes 121. The branches BR may be located in the samefirst layer L1 as the first resistance lines 151 and may be made of thesame material as the first resistance lines 151.

Each of the first connection lines 153 may electrically connect thefirst resistance lines 151 neighboring each other along the firstdirection X and may directly contact the first resistance lines 151. Thefirst connection lines 153 may be spaced apart from the first touchelectrode members 120 and the second touch electrode members 130 withoutcontacting the first touch electrode members 120 and the second touchelectrode members 130. In some exemplary embodiments, the firstconnection lines 153 may be located in the same second layer L2 as thefirst connection portions 123 and may be made of the same material asthe first connection portions 123.

In some exemplary embodiments, the insulating layer IL may be locatedbetween the first resistance lines 151 and the first connection lines153, and the first resistance lines 151 and the first connection lines153 may be connected to and directly contact each other through secondcontact holes CH2 formed in the insulating layer IL.

In the drawings, one first connection line 153 is disposed between firstresistance lines 151 neighboring each other along the first direction X.However, the number of the first connection lines 153 can be variouslychanged. For example, two or more first connection lines 153 may bedisposed between two neighboring first resistance lines 151 neighboringeach other along the first direction X.

Each of the second connection lines 155 may electrically connect thefirst resistance lines 151 located in electrode rows neighboring eachother along the second direction Y and may directly contact the firstresistance lines 151.

In some exemplary embodiments, each of the second connection lines 155may connect two of first resistance lines 151 neighboring each otheralong the second direction Y and located at ends of neighboringelectrode rows.

In some exemplary embodiments, the insulating layer IL may be locatedbetween the first resistance lines 151 and the second connection lines155, and the first resistance lines 151 and the second connection lines155 may be connected to and directly contact each other through thesecond contact holes CH2 formed in the insulating layer IL. The secondconnection lines 155 may be spaced apart from the first touch electrodemembers 120 and the second touch electrode members 130 withoutcontacting the first touch electrode members 120 and the second touchelectrode members 130. In some exemplary embodiments, the secondconnection lines 155 may be located in the same second layer L2 as thefirst connection portions 123 and may be made of the same material asthe first connection portions 123.

The exemplary connection relationship between the second connectionlines 155 and the first resistance lines 151 may be as follows.

A second connection line 155 located between the first electrode row RE1and the second electrode row RE2 may contact a first resistance line 151located in the first electrode row RE1 and the first electrode columnCE1 and a first resistance line 151 located in the second electrode rowRE2 and the first electrode column CE1. That is, the first resistanceline 151 located in the first electrode row RE1 and the first electrodecolumn CE1 and the first resistance line 151 located in the secondelectrode row RE2 and the first electrode column CE1 may be electricallyconnected to each other by the second connection line 155 locatedbetween the first electrode row RE1 and the second electrode row RE2.

A first resistance line 151 located in the second electrode row RE2 andthe eighth electrode column CE8 and a first resistance line 151 locatedin the third electrode row RE3 and the eighth electrode column CE8 maybe electrically connected to each other by a second connection line 155located between the second electrode row RE2 and the third electrode rowRE3.

A first resistance line 151 located in the third electrode row RE3 andthe first electrode column CE1 and a first resistance line 151 locatedin the fourth electrode row RE4 and the first electrode column CE1 maybe electrically connected to each other by a second connection line 155located between the third electrode row RE3 and the fourth electrode rowRE4.

A first resistance line 151 located in the fourth electrode row RE4 andthe eighth electrode column CE8 and a first resistance line 151 locatedin the fifth electrode row RE5 and the eighth electrode column CE8 maybe electrically connected to each other by a second connection line 155located between the fourth electrode row RE4 and the fifth electrode rowRE5.

A first resistance line 151 located in the fifth electrode row RE5 andthe first electrode column CE1 and a first resistance line 151 locatedin the sixth electrode row RE6 and the first electrode column CE1 may beelectrically connected to each other by a second connection line 155located between the fifth electrode row RE5 and the sixth electrode rowRE6.

A first resistance line 151 located in the sixth electrode row RE6 andthe eighth electrode column CE8 and a first resistance line 151 locatedin the seventh electrode row RE7 and the eighth electrode column CE8 maybe electrically connected to each other by a second connection line 155located between the sixth electrode row RE6 and the seventh electroderow RE7.

A first resistance line 151 located in the seventh electrode row RE7 andthe first electrode column CE1 and a first resistance line 151 locatedin the eighth electrode row RE8 and the first electrode column CE1 maybe electrically connected to each other by a second connection line 155located between the seventh electrode row RE7 and the eighth electroderow RE8.

That is, the first resistance lines 151 located in the sensing area SAmay all be connected in series to each other by the first connectionlines 153 and the second connection lines 155.

In some exemplary embodiments, the second connection lines 155 may allbe located within the sensing area SA as illustrated in FIG. 3.Alternatively, in an exemplary embodiment, a portion of each of thesecond connection lines 155 may be located in the peripheral area NSA.

The dummy electrodes 190 may be located in the second openings OP2 ofthe second touch electrodes 131. In some exemplary embodiments, thedummy electrodes 190 may be disposed in the second openings OP2,respectively. The second openings OP2 formed in the second touchelectrodes 131 may cause a difference in external light reflectance.Accordingly, pattern stains may be visible from the outside. The dummyelectrodes 190 reduce the difference in external light reflectance,thereby reducing the possibility of pattern stains being visible fromthe outside.

In some exemplary embodiments, the dummy electrodes 190 may have thesame shape as the second openings OP2. For example, when each of thesecond openings OP2 is shaped like a quadrilateral such as a rhombus,each of the dummy electrodes 190 may also be shaped like a quadrilateralsuch as a rhombus.

The dummy electrodes 190 may be disposed in the second openings OP2 andspaced apart from the second touch electrodes 131. That is, each of thedummy electrodes 190 may be an island pattern. In some exemplaryembodiments, each of the dummy electrodes 190 may be a floatingelectrode.

The dummy electrodes 190 may be located in the same first layer L1 asthe first touch electrodes 121, the second touch electrodes 131 and thefirst resistance lines 151 and may be made of the same material as thefirst touch electrodes 121, the second touch electrodes 131 and thefirst resistance lines 151.

In some exemplary embodiments, when the second touch electrodes 131 havea mesh structure, the dummy electrodes 190 may also have a meshstructure as illustrated in FIG. 10.

In some exemplary embodiments, first, second, and third wirings 901,903, and 903′ and signal lines 9111 and 9113 may be disposed on theperipheral area NSA of the base layer 110.

For example, the first, second, and third wirings 901, 903, and 903′ mayinclude a first wiring 901 connected to each of the first touchelectrode members 120, a second wiring 903 connected to an end of eachof the second touch electrode members 130, and a third wiring903'connected to the other end of each of the second touch electrodemembers 130. Here, the other end of each of the second touch electrodemembers 130 refers to an end opposite to an end of each second touchelectrode member 130 to which the second wiring 903 is connected. Thatis, a wiring connected to each of the second touch electrode members 130may have a double routing structure, which can improve aresistive-capacitive (RC) delay caused by the resistance of the secondtouch electrode members 130. However, the present disclosure is notlimited to this case. For example, the second wiring 903 may beconnected to an end of each of the second touch electrode members 130,and no wiring may be connected to the other end of each of the secondtouch electrode members 130, unlike in FIG. 3. That is, in an exemplaryembodiment, a wiring connected to each of the second touch electrodemembers 130 may have a single routing structure.

The signal lines 9111 and 9113 may include a first signal line 9111connected to an end of the strain gauge 150 and a second signal line9113 connected to the other end of the strain gauge 150.

In some exemplary embodiments, the first signal line 9111 may beconnected to an end of the strain gauge 150. For example, the firstsignal line 9111 may be connected to a first resistance line 151 locatedin the eighth electrode row RE8 and the eighth electrode column CE8 inthe strain gauge 150.

In some exemplary embodiments, the second signal line 9113 may beconnected to the other end of the strain gauge 150. For example, thesecond signal line 9113 may be connected to a first resistance line 151located in the first electrode row RE1 and the eighth electrode columnCE8 in the strain gauge 150.

In some exemplary embodiments, the first signal line 9111 and the secondsignal line 9113 may be located on the opposite side of the sensing areaSA from the first wirings 901. In some exemplary embodiments, the firstsignal line 9111 and the second signal line 9113 may be located in theperipheral area NSA, but may be located between the third wirings 903′and the sensing area SA.

Pad portions TP1 and TP2 may be located on the peripheral area NSA ofthe base layer 110. The pad portions TP1 and TP2 may be electricallyconnected to the wirings 901, 903 and 903′ and the signal lines 9111 and9113. In addition, the controller 200 may be electrically connected tothe pad portions TP1 and TP2.

In some exemplary embodiments, the pad portions TP1 and TP2 may includea first pad portion TP1 and a second pad portion TP2 spaced apart fromeach other along the first direction X. The first pad portion TP1 may beconnected to the second wirings 903 and the third wirings 903′, and thesecond pad portion TP2 may be connected to the first wirings 901.However, the present disclosure is not limited to this case. Forexample, the first pad portion TP1 and the second pad portion TP2 mayform one pad portion without being spaced apart from each other. Inaddition, wirings and signal lines connected to each of the first padportion TP and the second pad portion TP2 can be variously changed.

In the touch sensor TSM according to the above-described embodiment,since the first touch electrodes 121, the second touch electrodes 131and the first resistance lines 151 are located in the same first layerL1, they can be simultaneously formed in the same process, thussimplifying the manufacturing process. In addition, since the firsttouch electrodes 121, the second touch electrodes 131 and the firstresistance lines 151 are located in the same first layer L1, the touchsensor TSM can be implemented as a thin sensor while having a pressuresensing function.

Further, since the first connection lines 153 and the second connectionlines 155 of the strain gauge 150 are located in the same second layerL2 as the first connection portions 123, they can be formed at the sametime as the first connection portions 123 in the same process, thusfurther simplifying the manufacturing process.

In addition, since the strain gauge 150 is disposed substantially allover the sensing area SA, pressure sensing can be performed all over thesensing area SA, thus improving the convenience of operation of thedisplay device 1.

In some exemplary embodiments, the structure of the touch sensor TSM, inparticular, the position of the first resistance lines 151 may bechanged.

FIG. 15 is a cross-sectional view illustrating a modified structure ofFIG. 12. FIG. 16 is a cross-sectional view illustrating a modifiedstructure of FIG. 13. FIG. 17 is a cross-sectional view illustrating amodified structure of FIG. 14. Referring to FIGS. 15 through 17 inaddition to FIGS. 3 through 14, in some exemplary embodiments, firstresistance lines 151 may be located in a different layer from firsttouch electrodes 121, unlike in FIGS. 12 through 14. For example, thefirst resistance lines 151 may be located in the same second layer L2 asa first connection line 153, a second connection line 155 and a firstconnection portion 123. When the first resistance lines 151 are locatedin the second layer L2, they may be made of the same material as thefirst connection line 153, the second connection line 155 and the firstconnection portion 123 and may be formed together with the firstconnection line 153, the second connection line 155 and the firstconnection portion 123.

According to an exemplary embodiment, the base layer 110 serving as thebase of the sensor unit 100 may be a thin-film encapsulation layer of anorganic light emitting display panel. In this case, the base layer 110may be implemented as a multilayer including at least one organic layerand at least one inorganic layer or may be implemented as a single layerincluding a combination of organic and inorganic materials. For example,the base layer 110 may be a multilayer including at least two inorganiclayers and at least one organic layer interposed between the inorganiclayers. In a display device in which the base layer 110 is implementedas a thin-film encapsulation layer of an organic light emitting displaypanel, electrodes constituting the sensor unit 100 and componentsconstituting the display panel 300 may be formed on different surfacesof the base layer 110.

FIG. 18 is an enlarged plan view of a portion Q4 of FIG. 5. FIG. 19 is across-sectional view of the sensor unit 100 and the display panel 300taken along a sectional line X4-X4′ of FIG. 18.

Referring additionally to FIGS. 18 and 19, the sensor unit 100 mayinclude a thin-film encapsulation layer of the display panel 300 (inparticular, an organic light emitting display panel) as the base layer110. That is, the display panel 300 and the sensor unit 100 may beformed integrally with each other. Hereinafter, the thin-filmencapsulation layer 110 will be referred to with the same referencenumber with the base layer 110. For convenience, only a light emittingelement OLED (e.g., an organic light emitting diode) and one thin-filmtransistor TFT connected to the light emitting element OLED amongcomponents provided in each pixel of the display panel 300 areillustrated in FIG. 19.

The display panel 300 includes a base substrate 330, the light emittingelement OLED provided on a surface of the base substrate 330, and thethin-film encapsulation layer 110 provided on the light emitting elementOLED and covering at least the light emitting element OLED. In addition,according to an exemplary embodiment, the display panel 300 may furtherinclude at least one thin-film transistor TFT connected to the lightemitting element OLED. The thin-film transistor TFT may be locatedbetween the base substrate 330 and the light emitting element OLED.

The display panel 300 may further include at least one power supplyline, a signal line, and/or a capacitor not illustrated in the drawings.

According to an exemplary embodiment, the base substrate 330 may be arigid substrate or a flexible substrate, and the material of the basesubstrate 330 is not particularly limited. For example, the basesubstrate 330 may be a thin-film substrate having flexiblecharacteristics.

A buffer layer BFL is provided on the surface of the base substrate 330.The buffer layer BFL may prevent or limit the diffusion of impuritiesfrom the base substrate 330 and improve the flatness of the basesubstrate 330. The buffer layer BFL may be provided as a single layer,but may also be provided as a multilayer composed of at least twolayers. The buffer layer BFL may be an inorganic insulating layer madeof an inorganic material. For example, the buffer layer BFL may be madeof silicon nitride, silicon oxide, or silicon oxynitride.

The thin-film transistor TFT is provided on the buffer layer BFL. Thethin-film transistor TFT includes an active layer ACT, a gate electrodeGE, a source electrode SE, and a drain electrode DE. According to anexemplary embodiment, the active layer ACT may be provided on the bufferlayer BFL and may be made of a semiconductor material. For example, theactive layer ACT may be a semiconductor pattern made of polysilicon,amorphous silicon, or an oxide semiconductor. A region (e.g., a regionoverlapping the gate electrode GE) of the active layer ACT may not bedoped with an impurity, and the other region may be doped with animpurity.

A gate insulating layer GI may be provided on the active layer ACT, andthe gate electrode GE may be provided on the gate insulating layer GI.In addition, an interlayer insulating film ILA may be provided on thegate electrode GE, and the source electrode SE and the drain electrodeDE may be provided on the interlayer insulating film ILA. The sourceelectrode SE and the drain electrode DE may contact and be electricallyconnected to the active layer ACT respectively through contact holes CHApenetrating the gate insulating layer GI and the interlayer insulatingfilm ILA.

According to an exemplary embodiment, a passivation layer PSV isprovided on the source electrode SE and the drain electrode DE. Thepassivation layer PSV may cover the thin-film transistor TFT.

The light emitting element OLED is provided on the passivation layerPSV. The light emitting element OLED may include a first electrode EL1,a second electrode EL2, and a light emitting layer EML interposedbetween the first electrode EL1 and the second electrode EL2. Accordingto an exemplary embodiment, the first electrode EL1 of the lightemitting element OLED may be an anode. The first electrode EL1 of thelight emitting element OLED may contact and be electrically connected toan electrode (e.g., the drain electrode DE) of the thin-film transistorTFT through a contact hole CHB penetrating the passivation layer PSV.

A pixel defining layer PDL for defining a light emitting area PXA ofeach pixel is provided on the surface of the base substrate 330 on whichthe first electrode EL1 of the light emitting element OLED, etc. areformed. The pixel defining layer PDL may expose an upper surface of thefirst electrode EL1 and protrude from the base substrate 330 along theperiphery of each pixel area.

The light emitting layer EML is provided in the light emitting area PXAsurrounded by the pixel defining layer PDL. For example, the lightemitting layer EML may be disposed on the exposed surface of the firstelectrode EL1. According to an exemplary embodiment, the light emittinglayer EML may have a multilayer thin-film structure including at least alight generation layer. For example, the light emitting layer EML mayinclude a hole injection layer, a hole transport layer, a lightgeneration layer, a hole blocking layer (HBL), an electron transportlayer (ETL), and an electron injection layer (EIL). According to anexemplary embodiment, the color of light generated by the light emittinglayer EML may be one of red, green, and blue. Alternatively, the colorof light generated by the light emitting layer EML may be one ofmagenta, cyan, and yellow.

The second electrode EL2 of the light emitting element OLED may bedisposed on the light emitting layer EML. The second electrode EL2 ofthe light emitting element OLED may be a cathode.

The thin-film encapsulation layer 110 may be provided on the secondelectrode EL2 of the light emitting element OLED to cover the secondelectrode EL2 of the light emitting element OLED. The thin-filmencapsulation layer 110 seals the light emitting element OLED. Thethin-film encapsulation layer 110 includes at least one inorganic layer(hereinafter, referred to as an encapsulating inorganic layer). Thethin-film encapsulation layer 110 may further include at least oneorganic layer (hereinafter, referred to as an encapsulating organiclayer). The encapsulating inorganic layer protects the light emittingelement OLED from moisture/oxygen, and the encapsulating organic layerprotects the light emitting element OLED from foreign matter such asdust particles. When the light emitting element OLED is sealed by usingthe thin-film encapsulation layer 110, the thickness of the displaydevice 1 can be reduced, and flexible characteristics can be secured.

The thin-film encapsulation layer 110 may have a multilayer structure ora single-layer structure. For example, the thin-film encapsulation layer110 may include a first encapsulating inorganic layer 111, anencapsulating organic layer 112, and a second encapsulating inorganiclayer 113 sequentially stacked on the second electrode EL2.

In some exemplary embodiments, each of the first encapsulating inorganiclayer 111 and the second encapsulating inorganic layer 113 may be madeof silicon nitride, aluminum nitride, zirconium nitride, titaniumnitride, hafnium nitride, tantalum nitride, silicon oxide, aluminumoxide, titanium oxide, tin oxide, cerium oxide, silicon oxynitride(SiON), or lithium fluoride.

In some exemplary embodiments, the encapsulating organic layer 112 maybe made of acrylic resin, methacrylic resin, polyisoprene, vinyl resin,epoxy resin, urethane resin, cellulose resin, or perylene resin.

The structure of the thin-film encapsulation layer 110 is not limited tothe above example, and the stacked structure of the thin-filmencapsulation layer 110 can be variously changed.

The components of the second layer L2 described above may be disposed onthe thin-film encapsulation layer 110. The insulating layer IL may belocated on the second layer L2, and the first layer L2 may be located onthe insulating layer IL. In the drawings, the first touch electrodes 121are illustrated as components of the first layer L1. The first touchelectrodes 121 may have a mesh structure so as not to be visible to auser as described above and may be disposed to not overlap the lightemitting areas PXA. In other words, mesh hole overlapping a lightemitting area PXA, may be defined in each of the first touch electrodes121 having the mesh structure.

In the display device 1 according to the above-described embodiment, thedisplay panel 300 is implemented as an organic light emitting displaypanel having the thin-film encapsulation layer 110, and the componentsof the sensor unit 100 are disposed on the thin-film encapsulation layer110. For example, the first and second connection lines 153 and 155 ofthe strain gauge 150, the first connection portions 123 of the firsttouch electrode members 120, etc. may be disposed on the thin-filmencapsulation layer 110, the insulating layer IL may be disposed on thefirst and second connection lines 153 and 155 of the strain gauge 150,the first connection portions 123 of the first touch electrode members120, etc., and the first touch electrodes 121, the second touchelectrodes 131, the second connection portions 133, the first resistancelines 151 and the dummy electrodes 190 may be disposed on the insulatinglayer IL.

A touch position detection operation of the controller 200 will now bedescribed by additionally referring to FIG. 20.

FIG. 20 is a diagram for explaining a touch position detection operationof the touch sensor TSM according to an exemplary embodiment.

Referring additionally to FIG. 20, the touch driver 210 may provide thedriving signal Ts to the second touch electrode members 130 through thesecond wirings 903. In some exemplary embodiments, the driving signal Tsmay be sequentially provided to each of the second touch electrodemembers 130.

The touch detector 230 may receive the sensing signal Rs from each ofthe first touch electrode members 120 through the first wirings 901. Insome exemplary embodiments, the sensing signal Rs may includeinformation about a change in mutual capacitance between a first touchelectrode member 120 and a second touch electrode member 130 asdescribed above. When the driving signal Ts is provided to each of thesecond touch electrode members 130, mutual capacitance Cm is formedbetween each second touch electrode member 130 and each first touchelectrode member 120. When a touch input occurs, the mutual capacitanceCm may change, and the sensing signal Rs may include information aboutthe change in the mutual capacitance Cm.

In some exemplary embodiments, the touch detector 230 may include atleast one amplifier 231 such as an operational amplifier (OP amp), anADC 233, and a processor 235.

The amplifier 231 may include a first input terminal 231 a, a secondinput terminal 231 b, and an output terminal 231 c. According to anexemplary embodiment, the first input terminal 231 a of the amplifier231 (e.g., an inverting input terminal of an OP amp) may be electricallyconnected to each of the first touch electrode members 120 by the firstwirings 901, and the sensing signal Rs may be input to the first inputterminal 231 a.

In some exemplary embodiments, the second input terminal 231 b of theamplifier 231 (e.g., a non-inverting input terminal of the OP amplifier)may be a reference potential terminal and may be connected to, forexample, a reference power source. In some exemplary embodiments, thereference power source may be a ground (GND) power source. A sensingsignal Ns may be provided to the second input terminal 231 b of theamplifier 231. Accordingly, reference voltages of the amplifiers 231vary according to voltage variations of noise sensing electrode members170, respectively. That is, reference potentials of the amplifiers 231may vary according to potentials (voltage levels) of the noise sensingelectrode members 170, respectively.

In some exemplary embodiments, a capacitor C and a reset switch SW maybe connected in parallel to each other between the first input terminal231 a and the output terminal 231 c of the amplifier 231.

In the above example, the amplifier 231 is implemented as anon-inverting amplifier. However, in an exemplary embodiment, theamplifier 231 may also be implemented as an inverting amplifier.

The output terminal 231 c of the amplifier 231 may be electricallyconnected to the ADC 233.

The ADC 233 may convert an input analog signal into a digital signal. Insome exemplary embodiments, the ADC 233 may be provided as many as thenumber of the first touch electrode members 120 so that the ADCs 233 cancorrespond one-to-one to the first touch electrode members 120.Alternatively, in an exemplary embodiment, the first touch electrodemembers 120 may be configured to share one ADC 233. In this case, aswitch circuit for selecting a channel may be additionally provided.

The processor 235 processes a converted signal (digital signal) receivedfrom the ADC 233 and detects a touch input based on the signalprocessing result. For example, the processor 235 may comprehensivelyanalyze a first sensing signal amplified by the amplifier 231 andconverted by the ADC 233 to detect the occurrence of a touch input andthe position of the touch input. According to an exemplary embodiment,the processor 235 may be implemented as a microprocessor (MPU). In thiscase, a memory required for driving the processor 235 may beadditionally provided in the touch detector 230. However, theconfiguration of the processor 235 is not limited to this example. Inanother example, the processor 235 may be implemented as amicrocontroller (MCU).

The touch pressure detection operation of the controller 200 will bedescribed below by additionally referring to FIGS. 21 and 22.

FIG. 21 is a plan view schematically illustrating the arrangement of thestrain gauge 150, the first signal line 9111 and the second signal line9113 illustrated in FIG. 3 and the connection relationship of the straingauge 150, the first signal line 9111 and the second signal line 9113with a Wheatstone bridge circuit WB.

FIG. 22 is a circuit diagram of the Wheatstone bridge circuitelectrically connected to the strain gauge 150 of FIG. 21 for explaininga touch pressure detection operation of the touch sensor TSM accordingto an exemplary embodiment.

Referring to FIGS. 21 and 22, the strain gauge 150 may include a firstend E1 and a second end E2. As described above, the first end E1 of thestrain gauge 150 may be connected to the first signal line 9111, and thesecond end E2 of the strain gauge 150 may be connected to the secondsignal line 9113.

In some exemplary embodiments, both the first end E1 and the second endE2 of the strain gauge 150 may be located in the peripheral area NSA onone side of the sensing area SA. For example, the first end E1 and thesecond end E2 of the strain gauge 150 may be located on a left side ofthe sensing area SA, as illustrated in the drawings.

The pressure detector 250 may include the Wheatstone bridge circuit WB.

The Wheatstone bridge circuit WB includes a first node N1, a second nodeN2, a first output node N3, and a second output node N4. In someexemplary embodiments, the first node N1 may be provided with a drivingvoltage Vd, and the second node N2 may be provided with a referencevoltage Vref. In some exemplary embodiments, the reference voltage Vrefmay be a ground voltage.

In some exemplary embodiments, the Wheatstone bridge circuit WB mayfurther include a first resistor 251 a connected to the second node N2and the second output node N4, a second resistor 251 b connected to thefirst node N1 and the second output node N4, and a third resistor 251 cconnected to the second node N2 and the first output node N3.

In some exemplary embodiments, each of a resistance value R2 of thefirst resistor 251 a, a resistance value R3 of the second resistor 251 band a resistance value R4 of the third resistor 251 c may be apredetermined value. In an exemplary embodiment, each of the resistancevalue R2 of the first resistor 251 a, the resistance value R3 of thesecond resistor 251 b, and the resistance value R4 of the third resistor251 c may be a fixed value. In some exemplary embodiments, theresistance value R2 of the first resistor 251 a, the resistance value R3of the second resistor 251 b, and the resistance value R4 of the thirdresistor 251 c may be equal to each other.

In addition, in some exemplary embodiments, the Wheatstone bridgecircuit WB may further include a first element 253 connected to thefirst output node N3 and the second output node N4 and a second element255 connected to the first node N1 and the second node N2.

The first element 253 may sense an electrical flow between the firstoutput node N3 and the second output node N4. For example, the firstelement 253 may be a galvanometer or a voltage measurer.

The second element 255 may be a voltage supply element for supplying avoltage to the first node N1 and the second node N2. In some exemplaryembodiments, the second element 255 may provide the driving voltage Vdto the first node N1 and the reference voltage Vref to the second nodeN2.

In some exemplary embodiments, the first end E1 of the strain gauge 150may be electrically connected to the first node N1 by the first signalline 9111, and the second end E2 of the strain gauge 150 may beconnected to the first output node N3 by the second signal line 9113.Referring to FIG. 22, the resistance of the strain gauge 150 isrepresented as a variable resistance value Ra.

In the current embodiment, the strain gauge 150, the first resistor 251a, the second resistor 251 b, and the third resistor 251 c may beconnected to each other to implement a Wheatstone bridge.

In some exemplary embodiments, when a touch input is not applied, theresistance value Ra of the strain gauge 150 may be substantially equalto the resistance value R2 of the first resistor 251 a, the resistancevalue R3 of the second resistor 251 b, and the resistance value R4 ofthe third resistor 251 c.

When a touch input is not applied to the sensor unit 100, the resistancevalue R2 of the first resistor 251 a, the resistance value R3 of thesecond resistor 251 b, the resistance value R4 of the third resistor 251c and the resistance Ra of the strain gauge 150 may maintain anequilibrium state. In other words, the voltages of the first output nodeN3 and the second output node N4 may be equal to each other.

When a touch input is applied to the sensor unit 100, the shape of thestrain gauge 150, for example, the shape of a first resistance line 151may be changed according to the intensity of the touch or the appliedpressure. The changed shape of the strain gauge 150 may change theresistance value Ra of the strain gauge 150. Accordingly, a voltagedifference is generated between the first output node N3 and the secondoutput node N4. The voltage difference or the amount of currentgenerated by the voltage difference may be measured by the first element253 to detect the intensity of the touch or the pressure of the touch.

The electrical connection relationship of the strain gauge 150 and theWheatstone bridge circuit WB can be variously changed. For example, theposition of the strain gauge 150 and the position of the third resistor251 c in FIG. 22 can be reversed.

That is, the touch sensor TSM according to the current embodiment candetect the position of a touch using the first touch electrode members120, the second touch electrode members 130 and the touch driver 210 anddetect the intensity of pressure using the strain gauge 150 and thepressure detector 250.

The strain gauge 150 of the touch sensor TSM can be used as an inputdevice of various electronic devices including the display device 1. Thestrain gauge 150 can replace physical input buttons or can be used incombination with physical input buttons. For example, the intensity ofpressure may be detected using the strain gauge 150 and the pressuredetector 250, and a pre-programmed operation of the display device 1 maybe output according to the intensity of the pressure. For example, apre-programmed function such as screen locking, screen unlocking,execution of operations of specific hardware (e.g., sensors such asfingerprint sensors), screen conversion, application calling,application execution, photographing, or call receiving may beperformed.

Hereinafter, other embodiments will be described. In the followingembodiments, the same components as those described above will beindicated by the same reference numerals, and a redundant description ofthe components will be omitted or given briefly. The followingembodiments will be described, focusing mainly on differences from theprevious embodiment.

FIG. 23 is a plan view of a sensor unit 100-1 of a touch sensor TSM-1according to an exemplary embodiment and illustrates the connectionrelationship between the sensor unit 100-1 and a controller 200.

Referring to FIG. 23, the current embodiment is different from theexemplary embodiment of FIG. 3 in the configuration of the sensor unit100-1 of the touch sensor TSM-1. More specifically, the currentembodiment is substantially the same as or similar to the exemplaryembodiment of FIG. 3 except that a portion of each second connectionline 155 included in the sensor unit 100-1 is located in a peripheralarea NSA.

FIG. 24 is a plan view of a sensor unit 100-2 of a touch sensor TSM-2according to an exemplary embodiment and illustrates the connectionrelationship between the sensor unit 100_2 and a controller 200. FIG. 25is an enlarged view of a portion Q5 of FIG. 24. FIG. 26 illustrates thestructure of a first layer L1 of the sensor unit 100-2 of FIG. 25. FIG.27 illustrates the structure of a second layer L2 of the sensor unit100-2 of FIG. 25. FIG. 28 is a cross-sectional view taken along asectional line X11-X11′ of FIG. 25. FIG. 29 is a cross-sectional viewtaken along a sectional line X12-X12′ of FIG. 25. FIG. 30 is across-sectional view taken along a sectional line X13-X13′ of FIG. 25.FIG. 31 is a cross-sectional view taken along a sectional line X14-X14′of FIG. 25.

Referring to FIGS. 24 through 31, the touch sensor TSM-2 according tothe current embodiment includes the sensor unit 100-2 and the controller200.

The sensor unit 100-2 is substantially the same as or similar to thesensor unit 100 of FIG. 3 except that it includes a strain gauge 150-1and dummy electrodes 191. Therefore, differences will be mainlydescribed below.

The strain gauge 150-1 may be located within a sensing area SA and maybe located in rows formed by second touch electrodes 131 of second touchelectrode members 130. For example, the strain gauge 150-1 may belocated in a first row RO1, a second row RO2, a third row RO3, a fourthrow RO4, a fifth row RO5, a sixth row RO6, a seventh row RO7 and aneighth row RO8.

In some exemplary embodiments, each of the second touch electrodemembers 130 may be a driving electrode member as described above.

The strain gauge 150-1 may include second resistance lines 1511, thirdconnection lines 1531, and fourth connection lines 1551.

The second resistance lines 1511 may be located in second openings OP2formed in the second touch electrodes 131 and may be spaced apart fromthe second touch electrodes 131. In some exemplary embodiments, thesecond resistance lines 1511 may be located in the second openings OP2,respectively.

Each of the second resistance lines 1511 may be bent to have apredetermined pattern. In some exemplary embodiments, the shape of eachof the second resistance lines 1511 may be substantially the same as thestructure illustrated in FIG. 6. However, the shape of each of thesecond resistance lines 1511 can also be changed to shapes similar tothe structures illustrated in FIGS. 7 and 8.

Other features of the second resistance lines 1511 may be substantiallythe same as those of the first resistance lines 151 described above.

In some exemplary embodiments, the second resistance lines 1511 may belocated in the same first layer L1 as first touch electrodes 121 and thesecond touch electrodes 131. The 20 second resistance lines 1511 mayinclude a conductive material. In some exemplary embodiments, the secondresistance lines 1511 may be made of the same material as the firsttouch electrodes 121 and the second touch electrodes 131.

In some exemplary embodiments, each of the second resistance lines 1511may be formed by removing a portion of a mesh structure. In this case, aplurality of branches connected to the second resistance line 1511 maybe further located in each second opening OP2 as illustrated in FIG. 9.

Each of the third connection lines 1531 may electrically connect thesecond resistance lines 1511 neighboring each other along the firstdirection X and may directly contact the second resistance lines 1511.The third connection lines 1531 may be spaced apart from first touchelectrode members 120 and the second touch electrode members 130 withoutcontacting the first touch electrode members 120 and the second touchelectrode members 130. In some exemplary embodiments, the thirdconnection lines 1531 may be located in the same second layer L2 asfirst connection portions 123 and may be made of the same material asthe first connection portions 123.

In some exemplary embodiments, an insulating layer IL may be locatedbetween the second resistance lines 1511 and the third connection lines1531, and the second resistance lines 1511 and the third connectionlines 1531 may be connected to and directly contact each other throughthird contact holes CH3 formed in the insulating layer IL.

Although one of third connection line 1531 is illustrated as beingdisposed between second resistance lines 1511 neighboring each otheralong the first direction X, the present disclosure is not limited tothis case. Two or more third connection lines 1531 can also be disposedbetween two of second resistance lines 1511 neighboring each other alongthe first direction X.

Each of the fourth connection lines 1551 may electrically connect thesecond resistance lines 1511 located in rows neighboring each otheralong the second direction Y and may directly contact the secondresistance lines 1511.

In some exemplary embodiments, each of the fourth connection lines 1551may connect two of second resistance lines 1511 neighboring each otheralong the second direction Y and located at ends of neighboring rows.

In some exemplary embodiments, the insulating layer IL may be locatedbetween the second resistance lines 1511 and the fourth connection lines1551, and the second resistance lines 1511 and the fourth connectionlines 1551 may be connected to and directly contact each other throughthe third contact holes CH3 formed in the insulating layer IL. Thefourth connection lines 1551 may be spaced apart from first touchelectrode members 120 and the second touch electrode members 130 withoutcontacting the first touch electrode members 120 and the second touchelectrode members 130. In some exemplary embodiments, the fourthconnection lines 1551 may be located in the same second layer L2 as thefirst connection portions 123 and may be made of the same material asthe first connection portions 123.

The exemplary connection relationship between the fourth connectionlines 1551 and the second resistance lines 1511 may be as follows.

A fourth connection line 1551 located between the first row RO1 and thesecond row RO2 may contact a second resistance line 1511 located in thefirst row RO1 and a first column CO1 and a second resistance line 1511located in the second row RO2 and the first column CO. That is, thesecond resistance line 1511 located in the first row RO1 and the firstcolumn CO1 and the second resistance line 1511 located in the second rowRO2 and the first column CO1 may be electrically connected to each otherby the fourth connection line 1551 located between the first row RO1 andthe second row RO2.

A second resistance line 1511 located in the second row RO2 and aseventh column CO7 and a second resistance line 1511 located in thethird row RO3 and the seventh column CO7 may be electrically connectedto each other by a fourth connection line 1551 located between thesecond row RO2 and the third row RO3.

A second resistance line 1511 located in the third row RO3 and the firstcolumn CO1 and a second resistance line 1511 located in the fourth rowRO4 and the first column CO1 may be electrically connected to each otherby a fourth connection line 1551 located between the third row RO3 andthe fourth row RO4.

A second resistance line 1511 located in the fourth row RO4 and theseventh column CO7 and a second resistance line 1511 located in thefifth row RO5 and the seventh column CO7 may be electrically connectedto each other by a fourth connection line 1551 located between thefourth row RO4 and the fifth row RO5.

A second resistance line 1511 located in the fifth row RO5 and the firstcolumn CO1 and a second resistance line 1511 located in the sixth rowRO6 and the first column CO1 may be electrically connected to each otherby a fourth connection line 1551 located between the fifth row RO5 andthe sixth row RO6.

A second resistance line 1511 located in the sixth row RO6 and theseventh column CO7 and a second resistance line 1511 located in theseventh row RO7 and the seventh column CO7 may be electrically connectedto each other by a fourth connection line 1551 located between the sixthrow RO6 and the seventh row RO7.

A second resistance line 1511 located in the seventh row RO7 and thefirst column CO1 and a second resistance line 1511 located in the eighthrow RO8 and the first column CO1 may be electrically connected to eachother by a fourth connection line 1551 located between the seventh rowRO7 and the eighth row RO8.

That is, the second resistance lines 1511 located in the sensing area SAmay all be connected in series to each other by the third connectionlines 1531 and the fourth connection lines 1551.

Although the fourth connection lines 1551 are all located within thesensing area SA in the drawings, the present disclosure is not limitedto this case. At least a portion of each of the fourth connection lines1551 located on a left side of the sensing area SA in the drawings canalso be located in a peripheral area NSA.

The dummy electrodes 191 may be located in first openings OP1 of thefirst touch electrodes 121. In some exemplary embodiments, the dummyelectrodes 191 may be disposed in the first openings OP1, respectively.Like the dummy electrodes 190 (see FIG. 3) described above, the dummyelectrodes 191 may reduce a difference in external light reflectance,thereby reducing the possibility of pattern stains being visible fromthe outside.

In some exemplary embodiments, the dummy electrodes 191 may have thesame shape as the first openings OP1.

The dummy electrodes 191 may be disposed in the first openings OP1 andspaced apart from the first touch electrodes 121. Each of the dummyelectrodes 191 may be an island pattern. In some exemplary embodiments,each of the dummy electrodes 191 may be a floating electrode.

The dummy electrodes 191 may be located in the same first layer L1 asthe first touch electrodes 121, the second touch electrodes 131 and thesecond resistance lines 1511 and may be made of the same material as thefirst touch electrodes 121, the second touch electrodes 131 and thesecond resistance lines 1511.

In some exemplary embodiments, when the second touch electrodes 131 havea mesh structure, the dummy electrodes 191 may also have a meshstructure.

In some exemplary embodiments, a first signal line 9111 may be connectedto an end of the strain gauge 150-1. For example, the first signal line9111 may be connected to a second resistance line 1511 located in theeighth row RO8 and the seventh column CO7 in the strain gauge 150-1.

In some exemplary embodiments, a second signal line 9113 may beconnected to the other end of the strain gauge 150-1. For example, thesecond signal line 9113 may be connected to a second resistance line1511 located in the first row RO1 and the seventh column CO7 in thestrain gauge 150-1.

The strain gauge 150-1 may be connected to a Wheatstone bridge circuitWB (see FIG. 22) by the first signal line 9111 and the second signalline 9113 as described above.

The area of each of the second openings OP2 may be larger than the areaof each of the first openings OP1, and the length of one of secondresistance line 1511 may be greater than the length of one of firstresistance line 151 illustrated in FIG. 3. Therefore, in the currentembodiment, when touch inputs of the same pressure occur, a change inthe resistance of the strain gauge 150-1 may be larger than a change inthe resistance of the strain gauge 150 (see FIG. 3). That is, thecurrent embodiment has the advantage of improving pressure detectionsensitivity in addition to the effects described above.

In some exemplary embodiments, the structure of the touch sensor TSM-2,in particular, the position of the second resistance lines 1511 may bechanged.

FIG. 32 is a cross-sectional view illustrating a modified structure ofFIG. 28. FIG. 33 is a cross-sectional view illustrating a modifiedstructure of FIG. 29. FIG. 34 is a cross-sectional view illustrating amodified structure of FIG. 30. FIG. 35 is a cross-sectional viewillustrating a modified structure of FIG. 31. Referring to FIGS. 32through 35 in addition to FIGS. 24 through 31, in some exemplaryembodiments, second resistance lines 1511 may be located in a differentlayer from second touch electrodes 131, unlike in FIGS. 24 through 31.For example, the second resistance lines 1511 may be located in the samesecond layer L2 as a third connection line 1531, a fourth connectionline 1551 and a first connection portion 123. When the second resistancelines 1511 are located in the second layer L2, they may be made of thesame material as the third connection line 1531, the fourth connectionline 1551 and the first connection portion 123 and may be formedtogether with the third connection line 1531, the fourth connection line1551 and the first connection portion 123.

FIG. 36 is a plan view of a sensor unit 100-3 of a touch sensor TSM-3according to an exemplary embodiment and illustrates the connectionrelationship between the sensor unit 100-3 and a controller 200. FIG. 37is an enlarged view of a portion Q6 of FIG. 36. FIG. 38 illustrates thestructure of a first layer L1 of the sensor unit 100-3 of FIG. 37. FIG.39 illustrates the structure of a second layer L2 of the sensor unit100-3 of FIG. 37. FIG. 40 is a cross-sectional view taken along asectional line X21-X21′ of FIG. 37. FIG. 41 is a cross-sectional viewtaken along a sectional line X22-X22′ of FIG. 37.

Referring to FIGS. 36 through 41, the touch sensor TSM-3 according tothe current embodiment includes the sensor unit 100-3 and the controller200.

The sensor unit 100-3 is substantially the same as or similar to thesensor unit 100 of FIG. 3 except that it includes a strain gauge 150-2and does not include dummy electrodes (190 in FIG. 3). Therefore,differences will be mainly described below.

The strain gauge 150-2 may be located within a sensing area SA and maybe located in rows formed by first touch electrode members 120 and rowsformed by second touch electrodes 131 of second touch electrode members130. For example, the strain gauge 150-2 may be located in a firstelectrode row RE1, a first row RO1, a second electrode row RE2, a secondrow RO2, a third electrode row RE3, a third row RO3, a fourth electroderow RE4, a fourth row RO4, a fifth electrode row RE5, a fifth row RO5, asixth electrode row RE6, a sixth row RO6, a seventh electrode row RE7, aseventh row RO7, an eighth electrode row RE8 and an eighth row RO8.

The strain gauge 150-2 may include first resistance lines 151, secondresistance lines 1511, first connection lines 153, third connectionlines 1531, and fifth connection lines 1553.

The first resistance lines 151 may be located in first openings OP1 offirst touch electrodes 121, and each of the first connection lines 153may connect the first resistance lines 151 neighboring each other alongthe first direction X.

The second resistance lines 1511 may be located in second openings OP2of the second touch electrodes 131. Each of the third connection lines1531 may connect the second resistance lines 1511 neighboring each otheralong the first direction X.

In some exemplary embodiments, the first resistance lines 151, thesecond resistance lines 1511, the first touch electrodes 121 and thesecond touch electrodes 131 may be located in the first layer L1, andthe first connection lines 153, the third connection lines 1531 andfirst connection portions 123 may be located in the second layer L2.

Other features of the first resistance lines 151, the second resistancelines 1511, the first connection lines 153 and the third connectionlines 1531 may be substantially the same as those described above, andthus their description is omitted.

Each of the fifth connection lines 1553 may electrically connect a firstresistance line 151 and a second resistance line 1511 located in rowsneighboring each other along the second direction Y and may directlycontact the first resistance line 151 and the second resistance line1511.

In some exemplary embodiments, each of the fifth connection lines 1553may connect a first resistance line 151 and a second resistance line1511 neighboring each other along the second direction Y and located atends of neighboring rows.

In some exemplary embodiments, the second resistance lines 1511 and thefifth connection lines 1553 may contact each other through third contactholes CH3 formed in an insulating layer IL, and the first resistancelines 151 and the fifth connection lines 1553 may contact each otherthrough second contact holes CH2 formed in the insulating layer IL. Thefifth connection lines 1553 may be spaced apart from first touchelectrode members 120 and the second touch electrode members 130 withoutcontacting the first touch electrode members 120 and the second touchelectrode members 130. In some exemplary embodiments, the fifthconnection lines 1553 may be located in the same second layer L2 as thefirst connection portions 123 and may be made of the same material asthe first connection portions 123.

The exemplary connection relationship between the fifth connection lines1553, the first resistance lines 151 and the second resistance lines1511 may be as follows.

A first resistance line 151 located in the first electrode row RE1 and afirst electrode column CE1 and a second resistance line 1511 located inthe first row RO1 and a first column CO1 may be electrically connectedto each other by a fifth connection line 1553 located between the firstelectrode row RE1 and the first row RO1.

A second resistance line 1511 located in the first row RO1 and a seventhcolumn CO7 and a first resistance line 151 located in the secondelectrode row RE2 and an eight electrode column CE8 may be electricallyconnected to each other by a fifth connection line 1553 located betweenthe second electrode row RE2 and the first row RO1.

A structure similar to the above-described structure may be repeated.For example, when n is a natural number of 2 to 8, a first resistanceline 151 located in an n^(th) electrode row and the first electrodecolumn CE1 and a second resistance line 1511 located in an n^(th) rowand the first column CO1 may be connected to each other by a fifthconnection line 1553 located between the n^(th) electrode row and then^(h) row. In addition, a second resistance line 1511 located in then^(h) row and the seventh col CO7 and a first resistance line 151located in an (n+1)^(th) electrode row and the eighth electrode columnCE8 may be connected to each other by a fifth connection line 1553located between the n^(th) row and the (n+) electrode row.

That is, the first resistance lines 151 and the second resistance lines1511 located in the sensing area SA may all be connected in series toeach other by the first connection lines 153, the third connection lines1531 and the fifth connection lines 1553.

Although the fifth connection lines 1553 are all located in the sensingarea SA in the drawings, the present disclosure is not limited to thiscase. In some exemplary embodiments, a portion of each of the fifthconnection lines 1553 may be located in a peripheral area NSA.

In some exemplary embodiments, a first signal line 9111 may be connectedto an end of the strain gauge 150-2. For example, the first signal line9111 may be connected to a second resistance line 1511 located in theeighth row RO8 and the seventh column CO7 in the strain gauge 150-2.

In some exemplary embodiments, a second signal line 9113 may beconnected to the other end of the strain gauge 150-2. For example, thesecond signal line 9113 may be connected to a first resistance line 151located in the first electrode row RE1 and the eighth electrode columnCE8 in the strain gauge 150-2.

The strain gauge 150-2 may be connected to a Wheatstone bridge circuitWB (see FIG. 22) by the first signal line 9111 and the second signalline 9113 as described above.

In the current embodiment, the first resistance lines 151 are disposedin the first openings OP1, and the second resistance lines 1511 aredisposed in the second openings OP2. Accordingly, this can increase atouch pressure detectable area and increase the change in the resistanceof the strain gauge 150-2 due to pressure, thereby improving pressuredetection sensitivity.

In some exemplary embodiments, the structure of the touch sensor TSM-3,in particular, the positions of the first resistance lines 151 and thesecond resistance lines 1511 may be changed.

FIG. 42 is a cross-sectional view illustrating a modified structure ofFIG. 40. FIG. 43 is a cross-sectional view illustrating a modifiedstructure of FIG. 41. Referring to FIGS. 42 and 43 in addition to FIGS.36 through 41, in some exemplary embodiments, first resistance lines 151and second resistance lines 1511 may be located in a different layerfrom first touch electrodes 121 and second touch electrodes 131, unlikein FIGS. 36 through 41. For example, the first resistance lines 151 andthe second resistance lines 1511 may be located in the same second layerL2 as a first connection line 153, a third connection line 1531 and afirst connection portion 123. When the first resistance lines 151 andthe second resistance lines 1511 are located in the second layer L2,they may be made of the same material as the first connection line 153,the third connection line 1531 and the first connection portion 123 andmay be formed together with the first connection line 153, the thirdconnection line 1531 and the first connection portion 123 in the sameprocess.

The relative positions of the first resistance lines 151 and the secondresistance lines 1511 can be various changed. For example, the firstresistance lines 151 may be located in a first layer L1, and the secondresistance lines 1511 may be located in the second layer L2.Alternatively, the first resistance lines 151 may be located in thesecond layer L2, and the second resistance lines 1511 may be located inthe first layer L1.

FIG. 44 is a plan view of a sensor unit 100-4 of a touch sensor TSM-4according to an exemplary embodiment and illustrates the connectionrelationship between the sensor unit 100-4 and a controller 200.

Referring to FIG. 44, the current embodiment is different from theexemplary embodiment of FIG. 36 in the configuration of the sensor unit100-4 of the touch sensor TSM-4. More specifically, the currentembodiment is substantially the same as or similar to the exemplaryembodiment of FIG. 36 except that a portion of each fifth connectionline 1553 included in the sensor unit 100-4 is located in a peripheralarea NSA. Therefore, a redundant description is omitted.

In a touch sensor according to any of the above-described embodimentsand a display device including the touch sensor, since a strain gauge islocated in the touch sensor, the intensity of pressure can be detectedeven without a pressure sensor. In addition, the strain gauge can beformed in the process of manufacturing touch electrodes and connectionportions, and the addition of the strain gauge does not increase thethickness of the touch sensor. Further, since the strain gauge canreplace physical input buttons or can be used in combination withphysical input buttons, various user interfaces can be provided to auser.

According to embodiments, it is possible to provide a touch sensorcapable of sensing not only the position of a touch input but also thepressure of the touch input and a display device including the touchsensor.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

What is claimed is:
 1. A touch sensor comprising: a base layer; aninsulating layer disposed on the base layer, the insulating layerincluding a first surface facing the base layer and a second surfaceopposite to the first surface; first touch electrodes disposed directlyon the second surface of the insulating layer, each of the first touchelectrodes comprising a first opening; and a strain gauge comprising:resistance lines located in the first openings, respectively, theresistance lines disposed directly on the second surface of theinsulating layer; and a first connection line connecting two resistancelines neighboring each other along a first direction; wherein the firstconnection line is disposed between the base layer and the first surfaceof the insulating layer.
 2. The touch sensor of claim 1, wherein thefirst connection line overlaps at least two of the first touchelectrodes in a plan view.
 3. The touch sensor of claim 1, furthercomprising: a second connection line connecting two resistance linesneighboring each other along a second direction, the second directionintersecting the first direction, wherein the second connection line isdisposed between the base layer and the first surface of the insulatinglayer.
 4. The touch sensor of claim 1, wherein the first touchelectrodes and the resistance lines are made of the same material. 5.The touch sensor of claim 1, further comprising: a first connectionportion connecting two of first touch electrodes neighboring each otheralong the first direction, and wherein the first connection portion isdisposed directly on the second surface of the insulating layer.
 6. Thetouch sensor of claim 3, further comprising: second touch electrodesdisposed directly on the second surface of the insulating layer; and asecond connection portion connecting two of second touch electrodesneighboring each other along the second direction.
 7. The touch sensorof claim 6, wherein the second connection portion is disposed betweenthe base layer and the first surface of the insulating layer.
 8. Thetouch sensor of claim 6, wherein each of the second touch electrodescomprising a second opening, wherein the touch sensor further comprisesconductive patterns located in the second openings, respectively, andwherein a planar of each of the conductive patterns is different from aplanar of each of the resistance lines.
 9. The touch sensor of claim 8,wherein the conductive patterns are disposed directly on the secondsurface of the insulating layer.
 10. The touch sensor of claim 9,wherein the conductive patterns are spaced apart from the second touchelectrodes.
 11. The touch sensor of claim 8, wherein the first touchelectrodes, the second touch electrodes, the resistance lines and theconductive patterns are made of the same material.
 12. The touch sensorof claim 6, wherein each of the second touch electrodes comprising asecond opening, wherein the resistance lines are further located in thesecond openings, respectively.
 13. A display device comprising: a basesubstrate; a light emitting element located on the base substrate; aninorganic layer located on the light emitting element; an insulatinglayer disposed on the inorganic layer, the insulating layer including afirst surface facing the inorganic layer and a second surface oppositeto the first surface; touch electrodes disposed directly on the secondsurface of the insulating layer, each of the touch electrodes comprisingan opening; and a strain gauge comprising: resistance lines located inthe openings, respectively, the resistance lines disposed directly onthe second surface of the insulating layer; a first connection lineconnecting two resistance lines neighboring each other along a firstdirection; and a second connection line connecting two resistance linesneighboring each other along a second direction, the second directionintersecting the first direction, wherein the first connection line andthe second connection line are disposed between the inorganic layer andthe first surface of the insulating layer.
 14. The display device ofclaim 13, further comprising: an organic layer disposed between thelight emitting element and the inorganic layer.
 15. The display deviceof claim 13, wherein the touch electrodes have a mesh structure.
 16. Thedisplay device of claim 13, wherein the touch electrodes and theresistance lines are made of the same material.